Never read the books, but I read this.
Geraci becomes a boxer in his teens, eventually becoming a heavyweight champion under the moniker "Ace Geraci".
Winegartner living out some creepy fantasy, egomania behavior.
Tom Hagen trusts him [Momo Barone] enough to give him the job of killing a man who stole his watch.
Not believable.
Personally I was deterred from reading the books when I discovered the main character is some guy we've never heard of from the series.